The present invention relates to a means of controlling the wavelength of optical Wave Division Multiplex (WDM), High Density Wave Division Multiplex (HDWDM) or coherent-based transmitters in localized or distributed networks operating in burst mode (BM). Due to the Burst Mode Transmitters (BMTx) only transmitting data (and hence a detectable optical signal) for a very short time interval, standard wavelength control systems would have insufficient time to measure the BMTx wavelengths. The measurement system of the present invention xe2x80x9cstoresxe2x80x9d the optical BM data stream transmitted by each BMTx and presents this to a scanning based wavelength measurement system to measure the BMTx wavelength and hence determine the required wavelength correction. This would be applicable in Multi-wavelength Passive Optical Networks (PONs) for management of upstream traffic BMTx units.
According to the present invention there is provided an optical network operating with burst mode data traffic signals comprising a recirculating 8 optical loop memory including means to take a sample of a burst mode data traffic signal and to store the sample within the recirculating optical loop memory.
The present invention will now be described by way of example, with reference to the accompanying drawings, in which: